Introduction: The aim of present study was to investigate the effects of royal jelly (RJ) on the number of Nissl-stained neurons in caudate putamen unit (CPU) and substantia nigra pars compacta (SNC) and the thickness of gray (TGm) and white matter (TWm) of cerebral and cerebellar cortex in male rats with Parkinson’s disease (PD). Methods: Seventy five Sprague-Dawley adults’ male rats were used. Rats were randomly divided into 5 groups: 1- control intact rats; 2- sham; rats received 0.02% ascorbic acid diluted in saline by CPU injection 3- PD induction without treatment; 4 and 5- PD induction + 100 or 200 mg/kg/day RJ for 21 days started 4 weeks after lesion induction. PD induction was carried out by unilateral injection of 6-hydroxydopamine in CPU. The apomorphine were done one week before lesion as well as, second, fourth and seventh weeks after lesion. Nissl-stained neurons of SNC and CPU were counted. The thickness of gray and white matter was measured by histomorphometry. Results: data showed that RJ has corrected net contralateral turns of PD. RJ at both doses significantly (P<0.05) increased the number of Nissl-stained neurons in SNC and CPU in comparison to PD induction without treatment. RJ at low dose significantly (P<0.05) increased TGm and TWm of the cerebral cortex and it significantly (P<0.05) increased TGm but not TWm of cerebellum. RJ at high dose significantly (P<0.05) increased TGm and TWm in the cerebral cortex and cerebellum. Conclusion: Results indicate that RJ can improve PD symptoms; this effect was associated with histomorphometrical disorders.